Tire-pump.



B. S. COB.

TIRE PUMP. ABPLIOATION FILED 0GT.26, 1910.

Patented May 2, 1911.

WITNESSES:

' UNITED STATES PATENT OFFICE.

BENJAMIN S. COE, 0F BRIDGEPORT, CONNECTICUT, ASSIGNOR TO THE COE-STAPLEY MANUFACTURING COMPANY, OF BRIDGEPOBT, CONNECTICUT, A CORPORATION OF CONNECTICUT.

TIRE-PUMP.

Specification of Letters Patent.

Patented May 2, 1911.

To all whom it may concern:

Be it known that I, BENJAMIN S. Con, a

citizen of the United States, residing at Bridgeport, county of Fairfield, State of onnecticut, have invented an In'iprovement 111 TnePumps, of which the following is a specification.

This invention has for its object to produce a two-cylinder double-acting hand air pump adapted for general use and especially adapted for automobile use, in which the number of parts shall be reduced, the pump made more effective by doing away with waste air space, in which the cost of construction shall be reduced by various changes in the details of construction and which shall require the removal of but one screw plug in order to take out the pistons.

lVith these and other objects in view I have devised the novel pump of which the following description in connection with the accompanying drawing is a specification, reference characters being used to indicate the several parts:

Figure 1 is an elevation of my novel pump partly broken away; Fig. 2 an inverted plan view of the sheet metal cap plate removed; Fig. 3 a detail sectional view of the upper end of the small cylinder; Fig. 1 an inverted plan view of the sheet metal gland; and Fig. 5 is a plan view of the locking nut for the small cylinder.

10 denotes the large cylinder, 11 the small cylinder, 12 the large piston rod, 13 the small piston rod, 14; the small piston, 15 the handle which is rigidly secured to both piston rods, and 16 the base to which both cylinders are secured in any ordinary or preferred manner.

In pumps of this character as heretofore constructed, the upper ends of both cylinders have been seated in a relatively heavy cap. In my present pump, in lieu of a heavy double cap I use a smaller cap 17 which is engaged by the small cylinder only. This cap is provided at its lower end with an unthreaded opening 18, above which is a circular shoulder 19 and above the shoulder a larger threaded opening 20. The upper end of the small cylinder is provided with an outwardly extending flange 21 which rests upon the shoulder, a packing ring 22 being preferably interposed between the flange and the shoulder. The cylinder is rigidly but removably secured to the cap by a nut 23 which engages the thread of opening 20 and is provided with an angular opening in alineinent with the cylinder and for engagen'ient by a wrench or other setting tool. The upper end of opening 20 is closed by a screw plug 24 having a flange 25, a central hole 26 through which the small piston rod passes and at its lower end a threaded hub 27. The large cylinder is securely held in place by means of a sheet metal cap plate 28 having a flange 29 on its under side which closely receives the upper end of the large cylinder and is provided with a hole 30 through which the screw plug passes, packing rings 31 being interposed between the cap plate and the top of the cap and between the cap plate and the flange of the screw plug, so that when the screw plug is tightened up leakage of air at that point is made practically impossible.

In practice, the cylinders are made of uniform length and in the present instance I have shown the end of the cap plate which engages the screw plug as offset upward so as to rest upon the top of the cap. As air is taken in at the upper end of the large cylinder it is simply required to securely attach it in place but not necessary to make the connection air-tight.

32 denotes a sheet metal gland, the upper end of which is internally threaded to engage hub 27 of the screw plug, the lower end being reduced in diameter leaving an intermediate shoulder. Between the hub and the gland is a packing washer 33 which closely embraces the small piston rod. The upper surface of the shoulder is preferably provided with a circular groove and the lower end of the hub with a corresponding circular rib between which the packing washer is clamped, thus insuring a tight joint. The reduced lower end of the gland is made polygonal to receive a wrench or other tool in setting it up (see Fig. 4:).

34: denotes the nozzle which has threaded engagement with a hub 35 cast integral with cap 17. In my present pump I have simplified and cheapened this portion of the structure. Between the outer wall of the gland and the inner wall of the threaded opening in the cap is a circular air space 36- with which the small cylinder communicates through the opening in nut 23. A hole 37 is drilled in hub 35 obliquely outward and downward from the circular air space toward the center and a hole 38 is drilled upwf l'd and inward obliquely from the bot tom of the hub to intersect with hole 37. The lower end .of hole 38 is enlarged to receive a valve'39 and to receive the threaded hub i0 of the nozzle. This construction reduce the number of parts and greatly improves both the appearance and the operation of the pump.

The general operation of my novel pump is as usual in pumps of this character. Air from the small cylinder passes to the air space and through holes 37 and 38 to the nozzle.- During the down stroke of the pistons air is received behind the large piston and the air before the large piston is forced through a passage (not shown) in the base into the small cylinder and past the small piston and out through the nozzle. During theup stroke, air passes the large piston freely and air behind the small piston is forced out through the nozzle. To remove the pistons it is simply necessary to remove the screw plug. As the gland is on the under side of the screw plug and out of reach there is no danger of its being interferred with by inexperienced persons. It willbe noted that removal of the screw plug leaves the sheetmetal cap plate unattached so that the pistons are free to be drawn out. The pistons maybe of any ordinary or preferred construction. I preferably use pistons comprising cup-shaped flexible washers which are clamped between-metal washers at the ends" of the piston rods, the cup-shaped washer of the small. piston facing upward and the cup-shaped washer of the large piston (not shown) of course facing downward, so as to permit passage of air in both directions on the return stroke, which is the up stroke of the large piston and the down stroke of the small piston. The up stroke of the pistons is stopped by the engagement of the small piston with the lower end of the gland.

Having thus described my invention I claim:

In a pump, the combination with a cap having a shoulder, below the shoulder I .an unthreaded opening and above the shoulder a threaded opening, of a cylinder having an outwardly-turned flange resting on the shoulder and a nut engaging the thread above the shoulder and having an angular opening in alinement with the cylinder and for engagement by a tool in clamping the nut down upon the flange of the cylinder.

2. In a pump, the combination with a cylinder and piston rod, of a cap to which the cylinder is secured and which is provided "with a threaded opening above the cylinder, a screw plug engaging said opening and having a threaded hubat its lower end and a gland for the piston rod engaging the hub.

3. In a pump, the combination with a cylinder and piston rod, of a cap to which the cylinder is secured and which is provided with a threaded opening above the cylinder, a screw plug engaging said opening and having a threaded hub at its lower end, a gland. for the piston rod threaded to engage the hub and leaving a circular air space between the gland and the wall of the opening and having a reduced lower end, leaving an intermediate shoulder and a packing washer clamped between the shoulder and the end of the hub.

4. In a pump, the combination with a cylinder, a cap to which the cylinder is secured and which is provided with a threaded opening above the cylinder, and a hub integral with the cap, of a screw plug engaging the opening and a gland secured to the screw plug leaving a circular air space between the gland and the wall of the opening, said hub being provided with an oblique hole leading from the air space toward the center and an intersecting oblique hole leading from the bottom and a nozzle secured to the hub in alinement with the lower hole.

5. In a pump, the combination with large and small cylinders and a cap to which the small cylinder is secured and which is provided with a threaded opening above the cylinder, of a screw plug engaging said opening and a sheet met-a1 cap plate having a hole through which the screw plug passes and a flange which receives the end of the large cylinder.

6. In a pump, the combination with large and small cylinders, and a cap to which the small cylinder is secured, of a sheet metal cap plate secured to the cap by which the upper end of the large cylinder is secured.

7. In a pump, the combination with large and small cylinders and a cap to which the small cylinder is secured, of a screw plug engaging the cap and a sheet metal cap plate BENJAMIN S. GOE.

\Vitnesses S. W. ATHERTON, U. L. COATES.

Oo'piesof this patent may be obtained for. five cents each, by addressing the Commissioner of Patents, Washington, D. O. 

